The invention relates to a plastic component with a connecting element, wherein the connecting element has an attachment portion protruding at least partly from the plastic component.
In order to reduce emissions and lessen fuel consumption, efforts are being made in modern automobile design to reduce the overall weight of the vehicle. One approach here is the use of new materials, such as fiber-reinforced plastics for example, for the fabrication of structural components or outer skin components that were formerly manufactured for the most part from metallic materials, such as sheet metal. The use of carbon fiber-reinforced components or glass fiber-reinforced components has become established in the meantime.
Problems arise in the manufacturing of assemblies or subassemblies in which components made of fiber-reinforced plastic and components made of metallic material are combined involving the joining of these components. Known bonding techniques such as welding cannot be used for these material combinations.
A fastening device for a tank of an automobile is known from DE 10 2012 022 959 A1, including a roughly angle-shaped bracket for receiving the tank, the bracket consisting of a fiber composite plastic.
Starting from this prior art, the problem which the invention proposes to solve is the specification of a plastic component with which the drawbacks of the prior art are overcome. A special problem of the invention is to provide a plastic component which can be joined into an assembly with other components which are made of other materials.
This problem is solved by a plastic component according to the invention, which provides a plastic component with a connecting element, wherein the connecting element has an attachment portion which protrudes at least partly from the plastic component and an anchoring portion with which the connecting element is releasably joined to the plastic component. The anchoring portion can have a smaller cross sectional circumference than the attachment portion. Consequently, the cross sectional area or the cross section in the anchoring portion is in itself smaller than in the attachment portion. In this way, the connecting element can be introduced by its anchoring portion in an opening of a plastic component.
Reinforcement fibers in the context of this invention can be organic or inorganic reinforcement fibers. The reinforcement fibers can be formed of carbon fibers, for example. These form with the plastic matrix a carbon fiber-reinforced plastic, also known as CFP (carbon fiber-reinforced plastic). The corresponding fiber-reinforced plastic component is then a CFP component. The reinforcement fibers can also be formed as glass fibers, for example. These then form with the plastic matrix a glass fiber-reinforced plastic, also known as GFP. However, the invention should not be restricted to this, since one can also use reinforcement fibers made of aramid, polyester, nylon, polyethylene, DMNA, basalt, boron, ceramic, steel, natural fibers and/or a combination of these fibers. These fibers are then embedded in a plastic matrix.
The material of the plastic matrix may have, in particular, one or more thermoplastic plastics (thermoplasts) and/or duroplastic plastics (duroplasts). Fiber-reinforced plastics with a thermoplastic matrix have the advantage that they can be afterwards shaped or welded to other thermoplasts. Suitable as thermoplastic plastics are, e.g., polyether ketone (PEEK), polyphenylene sulfide (PPS), polysulfone (PSU), polyether imide (PEI) and/or polytetrafluoroethylene (PTFE). Fiber-reinforced plastics with a duroplastic matrix can no longer be shaped after the hardening or cross linking of the matrix. They have advantageously a high temperature application range. This holds especially for hot-hardening systems, which harden at high temperatures. Fiber-reinforced plastics with duroplastic matrix usually have the highest strength. One can use the following resins, e.g., as duroplastic plastics or the matrix: epoxy resins (EP), unsaturated polyester resin (UP), vinyl ester resin (VE), phenol-formaldehyde resin (PF), diallyl phthalate resin (DAP), methacrylate resin (MMA), polyurethane (PUR), amino resins, melamine resins (MF/MP) and/or urea resin (UF).
Furthermore, the attachment portion can be of an at least partly spherical shape. The spherical configuration offers the advantage that a second component with a shell-shaped bearing corresponding to the spherical shape and intended to be joined with the plastic component can be mounted on the sphere, making possible both a rotation and a tilting of the component about the spherical attachment portion. This offers the advantage that a torque and a force-free mounting of the second component on the spherical attachment portion is possible, so that little or no forces or torques are transmitted to the anchoring portion during the connecting of the plastic component to the second component.
Furthermore, the anchoring portion can include a shaft and a clamping device. In this way, the connecting element can be introduced in especially simple fashion into an opening of the plastic component, wherein the shaft protrudes through the opening and can be locked on the plastic component at an opposite side of the plastic component with the aid of the clamping device.
According to a first embodiment, the clamping device is configured in the form of a tensioner. Tensioners in the sense of the invention are levers functioning on the basis of a cam, whose eccentricity can be changed from an open position in which the connecting element is free of stress to a closed position in which the connecting element is tensioned, and vice versa. The tensioner can be fashioned as a quick release, so that the connecting element can be easily inserted into the plastic component and joined to it in a stationary manner.
In a second embodiment of the invention, the clamping device can also be configured as a screw closure. In this embodiment, the shaft has a thread on its axial end opposite the attachment portion, on which a nut can be screwed in order to secure the connecting element to the plastic component.
In both embodiments, the attachment portion can protrude from the plastic component on a first side of the plastic component and the anchoring portion can protrude at least partly on a second side of the plastic component, wherein the first and the second side of the plastic component lie opposite each other.
Furthermore, the plastic component can be a fiber-reinforced plastic component, wherein reinforcement fibers are arranged in a matrix.
According to one preferred embodiment, the plastic component is configured as a sandwich component with a core and at least one reinforcement layer. The reinforcement layer can be arranged on one side of the core or on both sides of the core. Alternatively, the core can also have the reinforcement layer wound or braided around it. The reinforcement layer is then fashioned as a cover layer or cover ply. The sandwich component has the advantage that the reinforcement layers are arranged at the margin, and thus confer high mechanical properties on the sandwich component, while a relatively more economical and lighter core can be placed on the inside.
Furthermore, an opening can be provided, which runs through the plastic component from its first side to its second side and in which at least the anchoring portion of the connecting element can be inserted.
Furthermore, an insert resistant to compressive force can be provided in the opening, by which a pretensioning force can be transmitted between the attachment portion of the connecting element and the clamping device. In this way, when the connecting element is mounted on the plastic component, one can avoid the plastic component being subjected to compressive forces due to pretensioning forces. Instead, the pretensioning force acts via the insert and a part of the plastic component on the clamping device. The insert can be fashioned as a bushing, edge bushing, or double edge bushing.
According to an especially preferred embodiment of the invention, the sandwich component includes a core, which is provided with a first cover layer, forming the first side of the plastic component, and with a second cover layer, forming the second side of the plastic component. The opening is fashioned as a round borehole, which has a first diameter in the area of the first cover layer and the core and a second diameter which is smaller than the first diameter in the area of the second cover layer. In this way, a step or collar formed in the circumferential direction is formed in the opening upon passing from the large diameter to the small diameter in the axial direction. The insert is introduced into the opening in the area of the larger diameter until it comes up against the encircling collar. During the tensioning of the connecting element, a flow of force is created from the attachment portion to the insert, across the encircling collar, to the second cover layer. A counter force is applied with the clamping device. The core is usually made of a resilient foam material, and thus is unsuited to absorbing the pretensioning forces. Upon application of pretensioning forces, the foam core would yield and show shrinkage effects, by virtue of which the connecting element would be loosened from the plastic component.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.